The main difference between the base model and the 2005 Hyundai Sonata GLS is better quality cloth upholstery and a stronger V6 engine.  The 2.7-liter engine hits 170-hp and 181 lb-ft of torque and is matched with a 4-speed auto tran.  Like the base GL, the 2005 Sonata GLS comes standard with dual front and front-side airbags, earning 4-star crash ratings.  Four-wheel disc brakes are standard on the mid-sized sedan, while ABS is optional.  Unlike the GL, traction control is available for the GLS.  

Riding on 16-inch alloy wheels, the 2005 Sonata GLS is equipped with the full power setup, plus cruise control, a CD player, foglights, leather trim, keyless entry, a tilt steering wheel, and a security system.  The GLS also adds heated mirrors, rear cupholders, and dual map lights to what you get on the GL, and this year the GLS Special Value trim comes standard with all that and heated front seats.  A sunroof is an available option.  The interior of the Sonata GLS is very spacious, even for rear legroom, and the trunk holds up to 14 cubic feet -- more with the rear seats folded down.  Owners are disappointed with the 19/27 mpg, which they say is an overestimate, and they complain that the seats are uncomfortable.  High points include the interior room, exterior styling, and long list of standard features.